Expulsion fuse



April 29, 1930. I J: F. DOHRWARDT 1,756,855

EXPULSION FUSE Filed June l2, 1929 Patented Apr. 29, 1930 UNITED STATESPATENT OFFICE JOHN F. DOHRWARDT, OF SOUTH MILWAUKEE, WISCONSIN, ASSIGNORTO LINE MA- TERIAL COMPANY, OF SOUTH MILWAUKEE, WISCONSIN, A COPORATIONOF 'WIS- CONSIN Application led J'une 12,

My invention relates to expulsion fuses of the type in which a fuse linkextends from one of the fuse terminals to a point beyond the other fuseterminal through a gas-tight tube member of insulating material,backwardly along the outer face of which tube member the link is doubledfor its connection to said other terminal, said tube member or asuitable extension thereof being open yto the atmosphere at or beyondthe point where the fuse link is doubled back, whereby the gasesgenerated in the tube upon the rupture or consumption of the `linktherein are permitted to escape freely from the fusebox. It is one ofthe objects of my invention to provide a new and improved form andarrangement of parts in an expulsion fuse of this type by which aneffective barrier is provided against the entrance of any gas into thefuse box after its escape from the end of the tube, such barrier beingarranged preferably to extend out some little distance from the face ofthe tube so as to increase materially the distance which the gas wouldhave to travel to get to the fuse terminal into effective aroingposition if a small quantity of the gas might seep into the box from theouter end of the tube structure or from the transversely opening fuseport in the side of the tube structure.

It is another object of my invention to improve devices of this type insundry details hereinafter pointed out. The preferred means by which Ihave accomplished my several objects are illustrated in the drawing andare hereinafter specifically described. That which I believe to be newand desire to cover by Letters Patent is set forth in the claims.

In the drawing, i Fig. 1 is a central vertical section through myimproved device, certain of the parts being shown in side elevation;

Fig. 2 is a bottom end view of the device as shown in Fig. 1, certain ofthe parts being EXPULSION FUSE 1929. Serial No. 370,258.

broken away at one side of the device forV -cover or lid 11 hingedlyconnected therewith .at one side in position for closing the side of thebox, such lid or cover 11 being adapted to swing outwardly anddownwardly about trunnions 12 forming part of the hinge means. Thearrangement is such that the cover 11 is adapted to be swung downwardlyinto vertical position so as to hang from the trunnions 12. The cover orlid 11 in the construction shown is formed of rubber or composition.

The box 10 in the construction shown is provided with bolts 13 extendingfrom its rear face for connection to any suitable support.

Upon the front face of the rear wall of the box 10, I have providedconnectors in the vform of spring clips or yokes 14 mounted in positionby means of screws 15 secured by means of screw threads in retainerblocks 16 mounted in the rear wall of the box. The screws 15 also holdin position plates 16a which have line terminals 17 formed integrallytherewith opposite openings `18 in the side Walls of the box. The sidewalls ofthe box above the openings 18 are provided with extensions 19serving to protect the openings 18 more or less completely against theentrance of water or other foreign matter. On the front face of the rearwall of the box, I have provided a barrier plate 20 extending forwardlybetween the line terminals 17.

the fuse terminals 21 and 22 are secured movably in position upon thefront face of the cover plate 11 by means of screws 23' engaging notchedlugs 24 formed integrally with the terminals 21 and 22, the arrangementbeing such that the terminals 21 and 22 are movable freely from side toside with respect to the cover plate 1 1. A tube 25 formed of insulatingmaterial extends from the terminal 21 through an opening in the terminal22 to a point located within an openingT 26 in the bottom wall of thebox l0, the opening 26 in the construction shown being in the form of anotch open at its forward end. Upon the lower end of the tube 25 belowthe fuse terminal 22, I have Amounted a barrier plate 27 which extendsoutwardly from,Y the face of the tube 25, being held fixedly in positionby means of a set screw 28. Upon the extreme lower end portion of thetube 25, I have provided a second tube 29 formed of insulating material,such tube 29 being secured in position upon the end of the tube 25 bymeans of screw threads. as is clearly shown in Fig 3, such tube member29 extending downwardly from the box 10 through the opening 26 and beingopen at its lower end outside. of the box. A fuse link 30 of anysuitable type is secured at its upper end to the fuse terminal 21 bymeans of a cap 31 removably mounted in position by means`of The fuselink 30 extends from the cap 31 downwardly7 through the tube 25 to apoint beyond the fuse terminal 22 and the barrier plate 27, extendingoutwardly in transverse position through a notch 32 in the side wall ofthe tube 25 near its lower end. As is best shown in Fig. 3, the bottomface of the barrier plate 27 is provided with a groove 33 along whichthe fuse link 30 extends so as to permit the face of the plate 27 to fitsnugly against the inner face of the bottom end wall of the box 1() forsubstantially closing the opening 26 about the tube structure comprisingthe members 25 and 29. The fuse link 30 is turned backwardly about thebarrier plate 27 for connection to the fuse terminal 22 by means of aSet screw 34, as is best shown in Fig. 1.

By my improved construction, the line terminals 17 areconnected by meanscomprising the fuse link 30 so long as the-cover plate 11 is in closedposition as shown in said Fig. 1, the

arrangement being such that the fuse4 link is connected in seriesbetween the wires which lextend through the openings 18'into the boxeration.

swinging movement of such` tube member with the cover plate 11 upon anopening 0p- This clearance is provided without detrimentwith respect tothe closure of the box by reason of the provision of the barrier plate27 which effectively closes the opening about the tube member 29.

lVhen it is desired to thread a new fuse 30 in position` the cap 31, theset screw 34, and the tube extension member 29 are all removed, thecover plate having first been turned to its open osition. The fuse isthen connected at its endportion by means of the cap 31, and the link isfolded hack about the barrier plate 27 and secured at its opposite endby the set screw 3l. The extension sleeve 29 is then secured in positionbringing the parts to the relative position as shown in Fig. 1,whereupon the cover plate 11 and the parts carried thereby can be swunginto operative position.

Not only is the barrier plate 27 effective for closing the opening aboutthe tube structure in the lower end of the box 1 0, but it is alsoeffective forshunting sidewise any gas which might seep through theopening in the side wall of the tube structure through which the fuselink 30 extends at the upper end of the sleeve member 29. Such gasdeflected by the plate 27 from a direct path upwardly toward theterminal 22 would be likely to pass down-` wardly through they notch 26without any tendency to enter the box at the oint between ltalle barrierplate 27 and the end wall of the lvhile I prefer to employ theconstruction substantially as shown in my drawing, it ils to beunderstood that I do not limit the invention tothe .form as shown exceptso far as the claims may be so limited by the prior art, it beingunderstood that changes might well be made in the construction withoutdeparting from the spirit of my invention.

1. A device of the type described, comprising in 4combination a fusebox, a line terminal in said box, a second line termina-l in said box inspaced relation to said first named terminal, a tube of insulatingmaterial extending from said first named terminal to said secondterminal and having an opening therefrom at a point beyond said second'terminal, a barrier surrounding said tube and extending outwardly fromits face at a point between said opening and said second terminal, and afuse link connected with said first named terminal and extendingtherefrom through the tube and turned backwardly about said barrier andconnected at its turned-back portion' with said second terminal.

2. A device of the type described, compris. ing in combination a fusebox, a line terminal in said box, a second line terminal in said box inspa-ced relation to-said first named terminal, a tube of insulatingmaterial extending from saidfirst named terminal to'said second terminaland having an opening therefrom at a point beyond said second terminal,a barrier surrounding said tube at a point between said openingr andsaid second terminal and serving substantially to close the end of thefuse box about the tube, and a fuse link connected with said firsf namedline terminal and extendingv therefrom through the tube and turnedbackwardly about said barrier and connected at its turned-back portionwith said second terminal.

3. A device of the type described, compris ing' in combination a fusebox, a line terminal in said box, a second line terminal in said box inspaced relation to said first named terminal, a tube ot' insulatingmaterial extending from said first named terminal to a point beyond saidsecond terminal. a second tube member of' insulating material heldremovably in position to act as an extension of said first named tubemember and opening at its lower end out' side of said fuse box, abarrier surrounding one of said tube members and serving substantiallyto close the end of the box about the tube, and a fuse link connectedwith said first named line terminal and extending therefrom through saidfirst named tube member and turned Vbackwardlv ,about said barrierandconnected at its turned-back portion with said second terminal.

4. A device of' the type described, comprising in combination a fusebox, a line terminal in said box, a second line terminal in said box inspaced relation to said first named terminal, a tube of insulatingmaterial extending from said first named terminal to a point beyond saidsecond terminal,l a second tube member of insulating material removablysecured on the end of said first named tube member and opening at itslower end outside of said fuse box, a barrier plate fixedly secured onsaid first named tube member adjacent to said second tube member andextending outwardly from its face, and a fuse link connected with saidfirst named line terminal and extending through said first named tubemember and extending transversely from said tube member at a point abovesaid second tube member and turned backwardly about said barrier plateand connected at its turned-back portion with said second terminal.

5. A device of the type described, comprising in combination a. fusebox, a line terminal in said box, a second line terminal in said ybox inspaced relation to said first named terminal, a tube of insulatingmaterial extending from said first named terminal to a point beyond saidsecond terminal, a second tube member of insulating material removablysecured on the end of said first named i, tube member .and opening atits lower end outside of said fusebox, a barrier plate fixedly securedon said first named tube member adjacent to said second tube member andextending outwardly from its face in position for closing the end ofsaid fuse box about the tube, and a fuse link connected with said firstnamed line terminal and extending through said first named tube memberand extending transversely from said tube member at a point above saidsecond tube member and turned backwardly about said barrier platt` andconnected at its turned-back portion with said second terminale 6. Adevice of the type described, comprising in combination a fuse box, aline terminal in said box, a second line terminal in said box in spacedrelation to said first named terminal, a tube structure of insulatingmaterial extending from said first named terminal with its lower endopen outside of the fuse box, a barrier mounted on said tube structurein position for closing about the tube the opening through which thetube projects from the box, and a fuse link connected with said firstnamed line terminal and extending through said tube structure and turnedback- -wardly about said barrier and connected at its turned-backportion with lsaid second terminal.

7 A device of the type described, comprising in combination a fuse box`a line terminal in said box. a second line terminal in said box inspaced relation to said first named terminal, a tube structure ofinsulating' material extending from said first named terminal with itslower end openoutside of the fuse box, a barrier mounted on said tubestructure in position for closing about the tube the opening throughwhich the tube projects from the box, and a fuse link connected withsaid first named line terminal and extending through said tube structureand outwardly through a small opening in the side of the tube struct-ureat a point below said barrier and turned backwardly about said barrierandconnected at its turned-back portion with said second terminal.

8. A device of the type described, comprising in combination a fuse box,a line terminal in said box, a second line terminal in said box inspaced relation to said firstv named terminal, a tube structure ofinsulating material extending from .said first named terminal with-'itslower end open outside of the fuse box, a barrier mounted on said tubestructure in position for closing about the tube the opening throughwhich the tube projects from the box, and a fuse link connected withsaid first named line 'terminal and extending through said tubestructure and outwardly through a small opening in the side of the tubestructure'at a point within the fuse box below said barrier and turnedbackwardly about said barrier and connected at its turnedback portionwith said second terminal.

9. A device of the type described, compris ing in combination a fusebox, a line terminal in said box, a second line terminal in said box inspaced relation to said first named terminal, a tube of insulatingmaterial extending from said first named terminal to-a point beyond saidsecond terminal, a second tube member ofinsulating material removablysecured on the end of said first named tube member andopening at itslower end outside of said fuse box, a barrier plate fixedly secured onsaid first named tube member adjacent to said second tube member andextending outwardly from its face in position for closing the end ofsaid fuse box about the tube, and a fuse link connected with said firstnamed line terminal and extending' through said tube structure andoutwardly through a notch in the lower end of said first named tubemember below said barrier substantially at the upper'end of said secondtube member and turned backwardly about said barrier and connected atits turned-back portion with said second terminal.

10. A device of the type described, comprising in combination a fusebox, a line terminal in Asaid box, a second line terminal in said box inspaced relation to said first named terminal, a tube of insulatingmaterial extending from said first named terminal to a point beyond saidsecond terminal, a second tube member of insulating material removablysecuredy on the lower end of said first named tube member and projectingfrom the fuse box through an opening inthe lower 'end'of the box, abarrier plate fixedlyl secured on said first named tube member abovesaid second tube member and extending outwardly from its face inposition for closing the end of the fuse box about the first named tubemember, and a fuse link con nected with said first named line terminaland extending through said first named tube member and outwardlv througha notch in the lower end of\said first named tube member at a pointlocated within'the opening through which the second tube memberprojects. from the fuse box and turned backwardly about said barrierplate and connected at its turned-back portion with said secondterminal.

11. A device of the type described, comprising in combination a fusebox, a cover plate 'hingedly connected with said box at its lower end, afuse terminal mounted-on the inner face of said cover plate near itsupper end, a second fuse terminal mounted on the inner face of saidcover plate near its lower end, r.' tube structure of insulatingmaterial extending from said first named fuse terlninal past said secondfuse terminal and projecting downwardly from the fuse box through .anotch in the lower lend of the box of such size as to provide clearancefor the end of said tube structure when the cover plate is swung toopenA position, a barrier mounted on said tube structure for closingsaid notch about said tube when the cover plate is in' operative closingposition, and

-a fuse link extending from said first named terminal 'through said tubestructure and about said barrier to saidsecond terminal.

12. A device of the 'type described, comprising in combination a fusebox, a cover plate hingedly connected with said box at its lower end, avfuse terminal mounted on the inner face of said cover plate near itsupperend, a second fuse terminal mounted on the inner face of said coverplate near its lower end, a tube structure of insulating materialextending from said first named fuse terminal through an opening in saidsecond fuse' terminal and projectingdownwardly from the fuse box througha notch in the lower end of the box of such size as to provide clearancefor the endof said tube structure when the cover plate is swung to openposition, a. barrier mounted on said tube structure for closing saidnotch about said tube when the cover plate is in operative closingposition, and a fuse link extending from said rst named terminal throughsaid tube structure and about said barrier' to said second terminal.

13. A device of the type described, comprising in combination a fusebox, a cover plate hingedly connected with said box at its lower end, afuse terminal mounted on the inner face of said cover plate near itsupper end, a second fuse terminal mounted on the inner face of saidcover plate near its lower end, a tube structure of insulating materialextending from said first named fuse terminal through an opening in saidsecond fuse terminal and projecting downwardly from the fuse box througha notch in the lower end of the box of such size as to provide clearancefor the end of said tube structure when the cover plate is swung to openposition, a barrier mountedon said tube structure in engagement with thelower end, wall of the box so as to close said notch about the-tube andadapted to swing upwardly out of engagement with said end wall when thecover plate is moved to open position, and a fuse link lextending fromsaid iirst named termi.` nal through said tube structure and about saidbarrier to said second terminal.

14. A device of the type described, comprising in combination a fusebox, a cover plate hingedly connected with said box at its lower end, afuse terminal mounted on the inner face of said cover plate near "itsupper end, a second fuse terminal mounted on the inner face of saidcover plate near its lower end, a tube of insulating material extendingfrom said first named fuse terminal through an opening in said secondfuse terminal, an extension tube member of insulating material removablysecured on said first named tube member and projecting downwardly fromthe fuse box through a notch in the lower end of the box of such size asto provide clearance for. the `extension member when the cover plate isswung to open position, a barrier mounted on said first named tubemember above said extension for closing said notch about said tube whenthe cover plate is in operative closing position, and a fuse linkextending from said lirst named terminal through said first named tubemem` ber and outwardly through a notch in the side Wall at the end ofsaid rst named tube member and doubled back about said barrier to saidsecond terminal.

JOHN F. DOHRWARDT.

